Co-rotating scroll compressor

ABSTRACT

Provided is a co-rotating scroll compressor which can alleviate the deformation caused by a centrifugal force generated in a scroll part. The present invention includes: a first driving side bearing and a second driving side bearing which rotatably support a driving side scroll member on shaft parts at one end side and the other end side in the axial direction, wherein a preload applied to a first driving side shaft part so that an axial clearance in the second driving side bearing direction is eliminated in the first driving side bearing, and a preload is applied to a second driving side shaft part so that an axial clearance in the first driving side bearing direction is eliminated in the second driving side bearing.

TECHNICAL FIELD

The present invention relates to a co-rotating scroll compressor.

BACKGROUND ART

Conventionally, co-rotating scroll compressors have been known (see PTL1). This includes a driving side scroll and a driven side scroll thatrotates synchronously with the driving side scroll, and offsets a drivenshaft that supports the rotation of the driven side scroll by a revoluteradius, with respect to a drive shaft that rotates the driving sidescroll, and rotates the drive shaft and the driven shaft at a sameangular velocity in a same direction.

CITATION LIST Patent Literature

[PTL 1] the Publication of Japanese Patent No. 5443132

SUMMARY OF INVENTION Technical Problem

In the co-rotating scroll compressor as in PTL 1, deformation isgenerated by a centrifugal force in a scroll part. In particular, in thecase of high-speed rotation, the deformation caused by the centrifugalforce can not be ignored.

In addition, when a temperature rises during the operation of theco-rotating scroll compressor, thermal stress may be generated in thescroll part.

The present invention has been made in view of such circumstances, andan object thereof is to provide a co-rotating scroll compressor capableof alleviating deformation caused by a centrifugal force generated in ascroll part.

Another object of the present invention is to provide the co-rotatingscroll compressor capable of alleviating thermal stress generated in thescroll part.

Solution to Problem

To solve the above problem, a co-rotating scroll compressor of thepresent invention employs the following solutions.

The co-rotating scroll compressor according to the present inventionincludes, a driving side scroll member rotatably driven by a drive part,having a plurality of spiral driving side wall bodies installed with apredetermined angular interval around the center of a driving side endplate, a driven side scroll member installed with the predeterminedangular interval around the center of a driven side end plate, havingthe number of spiral driven side wall bodies corresponding to each ofthe driving side wall bodies, and forming compression spaces by engagingeach of the driven side wall bodies with the corresponding driving sidewall bodies, a synchronous driving mechanism transmitting driving forcefrom the driving side scroll member to the driven side scroll member sothat the driving side scroll member and the driven side scroll membersynchronously revolve, a first driving side bearing and a second drivingside bearing rotatably supporting a shaft part at one end side and theother end side in an axial direction of the driving side scroll member,and a first driven side bearing and a second driven side bearingrotatably supporting the shaft part at one end side and the other endside in an axial direction of the driven side scroll member, a preloadis applied to the shaft part so that an axial clearance in a seconddriving side bearing direction is eliminated in the first driving sidebearing, and a preload is applied to the shaft part so that an axialclearance in a first driving side bearing direction is eliminated in thesecond driving side bearing, and/or a preload is applied to the shaftpart so that an axial clearance in a second driven side bearingdirection is eliminated in the first driven side bearing, and a preloadis applied to the shaft part so that an axial clearance in a firstdriven side bearing direction is eliminated in the second driven sidebearing.

Each of the driving side wall bodies arranged with the predeterminedangular interval around the center of the end plate of the driving sidescroll member is engaged with the corresponding driven side wall body ofthe driven side scroll member. Thereby, a plurality of pairs eachincluding one driving side wall body and one driven side wall body areprovided, and a scroll compressor having the wall body formed by aplurality of spirals is constituted. The driving side scroll member isrotatably driven by the drive part, and the driving force transmitted tothe driving side scroll member is transmitted to the driven side scrollmember via the synchronous driving mechanism. As a result, the drivenside scroll member rotates and performs rotation with respect to thedriving side scroll member in the same direction at the same angularspeed. In this way, the co-rotating scroll compressor is provided inwhich both the driving side scroll member and the driven side scrollmember rotate.

In the driving side scroll member, the first driving side bearing andthe second driving side bearing rotatably support the shaft parts on oneend side and the other end side in the axial direction. The rotation ofthe driving side scroll member generates a centrifugal force to deformthe driving side wall body of the driving side scroll member radiallyoutward. As described above, the radially outward deformation of theouter peripheral side of the driving side scroll member tends to causethe driving side scroll member to deform to decrease a distance to axialdirection between the shaft part supported by the first driving sidebearing and the shaft part supported by the second driving side bearing.Allowing such deformation further increases the deformation radiallyoutward on the outer peripheral side of the driving side scroll member.Therefore, a preload is applied to the shaft part so that an axialclearance in the second driving side bearing direction is eliminated inthe first driving side bearing, and a preload is applied to the shaftpart so that an axial clearance in the first driving side bearingdirection is eliminated in the second driving side bearing. Thereby,suppression of the deformation in which the distance to axial directionbetween both the shaft parts supported by each of the driving sidebearings decreases, can alleviate stress generated in the driving sidescroll member, further suppress leakage of compressed fluid generated bythe deformation of the driving side scroll member.

Similarly, in the driven side scroll member, the first driven sidebearing and the second driven side bearing rotatably support the shaftparts on one end side and the other end side in the axial direction. Therotation of the driven side scroll member generates the centrifugalforce to deform the driven side wall body of the driven side scrollmember radially outward. As described above, the radially outwarddeformation of the outer peripheral side of the driven side scrollmember tends to cause the driven side scroll member to deform todecrease a distance to axial direction between the shaft part supportedby the first driven side bearing and the shaft part supported by thesecond driven side bearing. Allowing such deformation further increasesthe deformation radially outward on the outer peripheral side of thedriven side scroll member. Therefore, a preload is applied to the shaftpart so that an axial clearance in the second driven side bearingdirection is eliminated in the first driven side bearing and a preloadis applied to the shaft part so that an axial clearance in the firstdriven side bearing direction is eliminated in the second driven sidebearing. Thereby, the suppression of the deformation in which thedistance to axial direction between both the shaft parts supported byeach of the driven side bearings decreases, can alleviate the stressgenerated in the driven side scroll member, further suppress the leakageof compressed fluid generated by the deformation of the driven sidescroll member.

Further, the co-rotating scroll compressor according to the presentinvention includes a driving side support member arranged via the drivenside end plate, fixed to a distal end side in the axial direction of thedriving side wall body and rotates together with the driving side scrollmember and a driven side support member arranged via the driving sideend plate, fixed to a distal end side in the axial direction of thedriven side wall body and rotates together with the driven side scrollmember, and the first driving side bearing supports the shaft part ofthe driving side scroll member, the second driving side bearing supportsthe shaft part of the driving side support member, the first driven sidebearing supports a bearing of the driven side support member, and thesecond driven side bearing supports the shaft part of the driven sidescroll member.

The shaft part of the driving side scroll member is supported by thefirst driving side bearing and the shaft part of the driving sidesupport member is supported by the second driving side bearing. Further,as described above, it is constituted that applying a preload to thefirst driving side bearing and the second driving side bearingsuppresses the deformation in which the distance to axial directionbetween both the shaft parts supported by each of the driving sidebearings decreases. Therefore, it is possible to suppress a fixing partof the distal end of the wall body of the driving side scroll member andthe driving side support member from being deformed radially outward dueto the centrifugal force.

The shaft part of the driven side support member is supported by thefirst driven side bearing and the shaft part of the driven side scrollmember is supported by the second driven side bearing. Further, asdescribed above, it is constituted that applying a preload to the firstdriven side bearing and the second driven side bearing suppresses thedeformation in which the distance to axial direction between both theshaft parts supported by each of the driven side bearings decreases.Therefore, it is possible to suppress the fixing part of the distal endof the wall body of the driven side scroll member and the driven sidesupport member from being deformed radially outward due to thecentrifugal force.

Further, in the co-rotating scroll compressor according to the presentinvention, the distal end side of the driving side wall body and thedriving side support member are fixed to allow displacement in the axialdirection, and each of the shaft parts is supported by a first drivingside bearing and a second driving side bearing, to allow an increase inthe distance between the shaft part supported by the first driving sidebearing and the shaft part supported by the second driving side bearing,and/or the distal end of the driven side wall body and the driven sidesupport member are fixed to allow the displacement in the axialdirection, and each of the shaft parts is supported by the first drivenside bearing and the second driven side bearing, to allow the increasein the distance between the shaft part supported by the first drivenside bearing and the shaft part supported by the second driven sidebearing.

The increase of temperature during the operation in the co-rotatingscroll compressor tends to cause the driving side scroll member and thedriving support member to thermally expand, and deform to increase thedistance to axial direction between both the shaft parts supported byeach of the driving side bearings. The restraint of the deformationleads to the increase in thermal stress generated in the driving sidescroll member and the driving side support member. Therefore, the distalend side of the driving side wall body and the driving side supportmember are fixed to allow the displacement in the axial direction, andeach of the shaft parts is supported by the first driving side bearingand the second driving side bearing, to allow the increase in thedistance between both the shaft parts supported by each of the drivingside bearings. As a result, the distance between both the shaft partssupported by each of the driving side bearings can be increasedaccording to the thermal expansion, so that the generation of thethermal stress can be suppressed.

For example, the distal end side of the driving side wall body and thedriving side support member may be slidably fixed by pins to allow thedisplacement in the axial direction. Further, for example, a preloaddirection of each driving side bearing may be set to cause the distalend side of the driving side wall body and the driving side supportmember to be displaceable in a direction in which the distance betweenboth shaft parts supported by each driving side bearing increases.

Similarly for the driven side, the increase of temperature during theoperation in the co-rotating scroll compressor tends to cause the drivenside scroll member and the driven support member to thermally expand,and deform to increase the distance to axial direction between both theshaft parts supported by each of the driven side bearings. The restraintof the deformation leads to the increase in the thermal stress generatedin the driven side scroll member and the driven side support member.Therefore, the distal end side of the driven side wall body and thedriven side support member are fixed to allow the displacement in theaxial direction, and each of the shaft parts is supported by the firstdriven side bearing and the second driven side bearing, to allow theincrease in the distance between both the shaft parts supported by eachof the driven side bearings. As a result, the distance between both theshaft parts supported by each of the driven side bearings can beincreased according to the thermal expansion, so that the generation ofthe thermal stress can be suppressed.

For example, the distal end side of the driven side wall body and thedriven side support member may be slidably fixed by pins to allow thedisplacement in the axial direction. Further, for example, the preloaddirection of each driven side bearing may be set to cause the distal endside of the driven side wall body and the driven side support member tobe displaceable in a direction in which the distance between both shaftparts supported by each driven side bearing increases.

Further, the co-rotating scroll compressor provided with, the drivingside scroll member including a first driving side scroll part having thefirst driving side end plate and the first driving side wall body,driven by the drive part, a second driving side scroll member having asecond driving side end plate and a second driving side wall body, and afixed portion of wall fixing the first driving side wall body and thesecond driving side wall body in a state in which the distal ends of thefirst driving side wall body and the second driving side wall body inthe axial direction face each other, the driven side scroll memberincluding a first driven side wall body provided on one side face of thedriven side end plate, engaged with the first driving side wall body,and a second driven side wall body provided on the other side face ofthe driven side end plate, engaged with the second driving side wallbody, a first support member arranged via the first driving side endplate, fixed to a distal end side in the axial direction of the firstdriven side wall body and rotating together with the first driven sidewall body and a second support member arranged via the second drivingside end plate, fixed to the distal end side in the axial direction ofthe second driven side wall body and rotating together with the seconddriven side wall body, wherein the first driving side bearing supports ashaft part of the first driving side scroll part, the second drivingside bearing supports a shaft part of the second driving side scrollpart, the first driven side bearing supports a bearing of the firstsupport member, and the second driven side bearing supports a shaft partof the second support member.

The shaft part of the first driving side scroll part is supported by thefirst driving side bearing and the shaft part of the second driving sidescroll part is supported by the second driving side bearing. Further, asdescribed above, it is constituted that applying a preload to the firstdriving side bearing and the second driving side bearing suppresses thedeformation in which the distance to axial direction between both theshaft parts supported by each of the driving side bearings decreases.Therefore, it is possible to suppress the fixed portion of wall of thedriving side scroll member from being deformed radially outward due tothe centrifugal force.

The shaft part of the first support member is supported by the firstdriven side bearing and the shaft part of the second support member issupported by the second driven side bearing. Further, as describedabove, it is constituted that applying a preload to the first drivenside bearing and the second driven side bearing suppresses thedeformation in which the distance to axial direction between both theshaft parts supported by each of the driven side bearings decreases.Therefore, it is possible to suppress the fixing part of the distal endof each driven side wall body and each of the driven side supportmembers from being deformed radially outward due to the centrifugalforce.

Further, in co-rotating scroll compressor, the fixed portion of wall isfixed to allow the displacement in the axial direction, and each of theshaft parts is supported by a first driving side bearing and a seconddriving side bearing, to allow the increase in the distance between theshaft part supported by the first driving side bearing and the shaftpart supported by the second driving side bearing, and/or the distal endof each of the driven side wall bodies and each of the support membersis fixed to allow the displacement in the axial direction, and each ofthe shaft parts is supported by a first driven side bearing and a seconddriven side bearing, to allow the increase in the distance between theshaft part supported by the first driven side bearing and the shaft partsupported by the second driven side bearing.

The increase of temperature during the operation in the co-rotatingscroll compressor tends to cause the driving side scroll member tothermally expand, and deform to increase the distance to axial directionbetween both the shaft parts supported by each of the driving sidebearings. The restraint of the deformation leads to the increase in thethermal stress generated in the driving side scroll member. Therefore,the fixed portion of wall is fixed to allow the displacement in theaxial direction, and each of the shaft parts is supported by the firstdriving side bearing and the second driving side bearing, to allow theincrease in the distance between both the shaft parts supported by eachof the driving side bearings. As a result, the distance between both theshaft parts supported by each of the driving side bearings can beincreased according to the thermal expansion, so that the generation ofthe thermal stress can be suppressed.

For example, as for the fixed portion of wall, a pin is used to allowthe displacement in the axial direction. Further, for example, thepreload direction of each driving side bearing may be set to bedisplaceable in the direction in which the distance between both shaftparts supported by each driving side bearing increases.

Similarly for the driven side, the increase of temperature during theoperation in the co-rotating scroll compressor tends to cause the drivenside scroll member and the driven side support member to thermallyexpand, and deform to increase the distance to axial direction betweenboth the shaft parts supported by each of the driven side bearings. Therestraint of the deformation leads to the increase in the thermal stressgenerated in the driven side scroll member and each of the supportmembers. Therefore, the distal end of each driven side wall body andeach of the support members are fixed to allow the displacement in theaxial direction, and each of the shaft parts is supported by the firstdriven side bearing and the second driven side bearing, to allow theincrease in the distance between both the shaft parts supported by eachof the driven side bearings. As a result, the distance between both theshaft parts supported by each of the driven side bearings can beincreased according to the thermal expansion, so that the generation ofthe thermal stress can be suppressed.

For example, the distal end of each driven side wall body and each ofthe support members may be fixed by pins to allow it to displace in theaxial direction. Further, for example, the preload direction of eachdriven side bearing may be set to be displaceable in a direction inwhich the distance between both shaft parts supported by each drivenside bearing increases.

Further, the co-rotating scroll compressor according to the presentinvention includes a first housing having a bearing fixing part to whichthe first driving side bearing and the first driven side bearing arefixed, and a second housing contacted against and fixed to the firsthousing in the axial direction, and having a bearing fixing part towhich the second driving side bearing and the second driven side bearingare fixed. Contacting the first housing and the second housing eachother in the axial direction to be fixed applies a preload to both thedriving side bearings and/or both the driven side bearings.

Contacting the first housing and the second housing each other in theaxial direction to be fixed applies a preload to the bearings, so thatit is unnecessary to provide a preload member (such as a nut) forapplying a preload. As a result, the number of parts can be reduced, andassembling property is improved.

Further, in the co-rotating scroll compressor according to the presentinvention, the first driving side bearing is provided on the shaft parton the opposite side sandwiching the drive part as seen from the drivingside end plate of the driving side scroll member.

The first driving side bearing is provided on the shaft part on theopposite side sandwiching the drive part (for example, an electricmotor) as seen from the driving side end plate. Thereby, it is notnecessary to provide the driving side shaft part between the drivingside end plate and the drive part, and the number of parts can bereduced. Even if the driving side shaft part is provided between thedriving side end plate and the drive part, applying a preload by thefirst driving side bearing provided on the opposite side of the drivepart can reduce a burden on the driving side shaft part provided betweenthe driving side end plate and the drive part.

Advantageous Effects of Invention

A preload is applied to the shaft part to eliminate an axial clearancebetween each of the bearings, so that it is possible to alleviate achange caused by the centrifugal force generated in the scroll member.

Fixing to allow the displacement in the axial direction of the fixingpart and allowance of the increase in the distance between the shaftssupported by each of the bearings can suppress the generation of thethermal stress.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal section view showing a co-rotating scrollcompressor according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a driving side scroll member of FIG. 1.

FIG. 3 is a plan view showing a driven side scroll member of FIG. 1.

FIG. 4 is a longitudinal section view showing a contact angle caused bya preload of a bearing shown in FIG. 1.

FIG. 5 shows deformation caused by centrifugal force of the driving sidescroll member, wherein FIG. 5(a) is a schematic diagram showing alongitudinal section view according to a reference example, and FIG.5(b) is a schematic diagram showing a longitudinal section viewaccording to the first embodiment.

FIG. 6 shows deformation caused by a thermal expansion of the drivingside scroll member, FIG. 6(a) is a schematic view showing a longitudinalsection view according to a reference example, and FIG. 6(b) is aschematic view showing a longitudinal section view according to thefirst embodiment.

FIG. 7 is a longitudinal section view showing a co-rotating scrollcompressor according to a second embodiment of the present invention.

FIG. 8 is a longitudinal section view showing Modification 1 of how apreload is applied to bearings of a co-rotating scroll compressor.

FIG. 9 is a longitudinal section view showing an example in which aposition of a preload member is changed with respect to FIG. 8.

FIG. 10 is a longitudinal section view showing an example in which theposition of the preload member is changed with respect to FIG. 8.

FIG. 11 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification1.

FIG. 12 is a longitudinal section view showing Modification 2 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 13 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification2.

FIG. 14 is a longitudinal section view showing Modification 3 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 15 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification3.

FIG. 16 is a longitudinal section view showing Modification 4 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 17 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification4.

FIG. 18 is a longitudinal section view showing Modification 5 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 19 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification5.

FIG. 20 is a longitudinal section view showing Modification 6 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 21 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification6.

FIG. 22 is a longitudinal section view showing Modification 7 of how apreload is applied to the bearings of the co-rotating scroll compressor.

FIG. 23 is a table showing a combination of fitting of the respectivebearings and presence or absence of the preload member of Modification7.

FIG. 24 is a longitudinal section view showing Modification 8 of theco-rotating scroll compressor of FIG. 1.

DESCRIPTION OF EMBODIMENTS First Embodiment

Hereinafter, a first embodiment of the present invention will bedescribed with reference to FIG. 1 or the like.

FIG. 1 shows a co-rotating scroll compressor 1A. The co-rotating scrollcompressor 1A can be used as a supercharger for compressing combustionair (fluid) supplied to an internal combustion engine such as vehicleengines.

The co-rotating scroll compressor 1A includes a housing 3, a motor(drive part) 5 housed on one end side of the housing 3, a driving sidescroll member 70 and a driven side scroll member 90 housed on the otherend side of the housing 3.

The housing 3 has a substantially cylindrical shape and includes a motorhousing part (first housing) 3 a housing the motor 5 and a scrollhousing part (second housing) 3 b housing the scroll members 7 and 9.

Cooling fins 3 c cooling the motor 5 are provided on the outer peripheryof the motor housing part 3 a. A discharge port 3 d dischargingcompressed air is formed at an end part of the scroll housing part 3 b.Although not shown in FIG. 1, the housing 3 is provided with an airintake port for drawing in air.

The scroll housing part 3 b of the housing 3 is divided by a dividingface P positioned substantially at the center in the axial direction ofthe scroll members 70 and 90. As shown in FIG. 4 to be described later,the housing 3 is provided with a flange part (fastening part) 30protruding outward at a predetermined position in a circumferentialdirection. Bolts 32 as fastening means are fixed trough the flange part30 so that the dividing face P is fastened.

The electric power supplied from the power supply source which is notshown drives the motor 5. An instruction from a control unit which isnot shown controls rotation of the motor. A stator 5 a of the motor 5 isfixed to the inner peripheral side of the housing 3. A rotor 5 b of themotor 5 rotates around a driving side rotation axis CL1. A drive shaft 6extending on the driving side rotation axis CL1 is connected to therotor 5 b. The drive shaft 6 is connected to a first driving side shaftpart 7 c of the driving side scroll member 70.

At the rear end (right end in FIG. 1) of the drive shaft 6, that is, theend part of the drive shaft 6 opposite to the driving side scroll member70, a rear end bearing 17 that rotatably supports the drive shaft 6between the drive shaft 6 and the housing 3 is provided.

The driving side scroll member 70 includes a first driving side scrollpart 71 on the motor 5 side and a second driving side scroll part 72 onthe discharge port 3 d side.

The first driving side scroll part 71 includes a first driving side endplate 71 a and a first driving side wall body 71 b.

The first driving side end plate 71 a is connected to the first drivingside shaft part 7 c connected to the drive shaft 6, and extends in adirection orthogonal to the driving side rotation axis CL1. The firstdriving side shaft part 7 c is rotatably provided with respect to thehousing 3 via a first driving side bearing 11 which is an angular ballbearing.

The first driving side end plate 71 a has a substantially disk shape ina plan view. As shown in FIG. 2, three, that is, triple spirals of thefirst driving side wall bodies 71 b which are formed to spiral areprovided on the first driving side end plate 71 a. The first drivingside wall bodies 71 b having triple spirals are arranged at equalintervals around the driving side rotation axis CL1. Winding end parts71 e of the first driving side wall bodies 71 b are not fixed to theother wall parts, but are independent from each other. That is, no wallpart is provided to reinforce the first driving side wall bodies 71 b byconnecting the winding end parts 71 e together.

As shown in FIG. 1, the second driving side scroll part 72 includes asecond driving side end plate 72 a and a second driving side wall body72 b. The second driving side wall body 72 b has triple spiralssimilarly to the above-described first driving side wall body 71 b (seeFIG. 2).

A second driving side shaft part 72 c extending in a direction of thedriving side rotation axis CL1 is connected to the second driving sideend plate 72 a. The second driving side shaft part 72 c is rotatablyprovided with respect to the housing 3 via a second driving side bearing14 which is the angular ball bearing. On the side of the inner ring ofthe second driving side bearing 14, a preload member 14 a such as a nut,a disk spring is provided. The preload member 14 a is attached to thesecond driving side shaft part 72 c and is fixed to press the inner ringof the second driving side bearing 14 toward the first driving sidebearing 11 side. As a result, an axial clearance between the enlargeddiameter shoulder part of the second driving side shaft part 72 c andthe side face of the second driving side bearing 14 is made zero.

A discharge port 72 d is formed on the second driving side shaft part 72c along the driving side rotation axis CL1.

The first driving side scroll part 71 and the second driving side scrollpart 72 are fixed in a state in which the distal ends (free ends) of thewall bodies 71 b and 72 b face each other. The first driving side scrollpart 71 and the second driving side scroll part 72 are fixed to eachother by pins (fixed portion of wall) 31 fastened to the flange parts 73provided at a plurality of positions in the circumferential direction toprotrude outward in the radial direction. Fixing by the pin 31 allowsthe first driving side scroll part 71 and the second driving side scrollpart 72 to move in the direction away from each other along the axialdirection (horizontal direction in FIG. 1).

The driven side scroll member 90 has a driven side end plate 90 aprovided substantially at the center in the axial direction (horizontaldirection in the drawing). A through hole 90 h is formed in the centerof the driven side end plate 90 a so that the compressed air flows tothe discharge port 72 d.

On both sides of the driven side end plate 90 a, driven side wall bodies91 b and 92 b are provided, respectively. The first driven side wallbody 91 b installed on the motor 5 side from the driven side end plate90 a is engaged with the first driving side wall body 71 b of the firstdriving side scroll part 71, and the second driven side wall body 92 binstalled on the discharge port 3 d side from the driven side end plate90 a is engaged with the second driving side wall body 72 b of thesecond driving side scroll part 72.

As shown in FIG. 3, three, that is, triple spirals of the first drivenside wall bodies 91 b having the outer peripheral end part 91 e areprovided. The driven side wall bodies 9 b having triple spirals arearranged at equal intervals around the driven side rotation axis CL2.The second driven side wall body 92 b has also the same configuration.

A first support member 33 and a second support member 35 are provided onboth ends of the driven side scroll member 90 in the axial direction(horizontal direction in the drawing). The first support member 33 isarranged on the motor 5 side and the second support member 35 isarranged on the discharge port 3 d side. The first support member 33 isfixed to the distal end (free end) of the first driven side wall body 91b by a pin 25 a, and the second support member 35 is fixed to the distalend (free end) of the second driven side wall body 92 b by a pin 25 b.Fixing the pins 25 a and 25 b causes the wall bodies 91 b and 92 b andthe support members 33 and 35 to move in the direction away from eachother along the axial direction (horizontal direction in FIG. 1).

On the center shaft side of the first support member 33, there isprovided a first support member shaft part 33 a, which is fixed to thehousing 3 via a first support member bearing (first driven side bearing)37 which is the angular ball bearing. On the center shaft side of thesecond support member 35, there is provided a second support membershaft part 35 a, which is fixed to the housing 3 via a second supportmember bearing (second driven side bearing) 38 which is the angular ballbearing. As a result, the driven side scroll member 90 rotates aroundthe driven side rotation axis CL2 via each of the support members 33 and35.

A pin ring mechanism (synchronous driving mechanism) 15 is providedbetween the first support member 33 and the first driving side end plate71 a. That is, a ring member 15 a is provided on the first driving sideend plate 71 a, and a pin member 15 b is provided on the first supportmember 33. The pin ring mechanism 15 is used as the synchronous drivingmechanism transmitting driving force from the driving side scroll member70 to the driven side scroll member 90 so that both the scroll members70 and 90 synchronously revolve.

A pin ring mechanism (synchronous driving mechanism) 15 is providedbetween the second support member 35 and the second driving side endplate 72 a. That is, a ring member 15 a is provided on the seconddriving side end plate 72 a, and a pin member 15 b is provided on thesecond support member 35. The pin ring mechanism 15 is used as thesynchronous driving mechanism transmitting the driving force from thedriving side scroll member 70 to the driven side scroll member 90 sothat both the scroll members 70 and 90 synchronously revolve.

In FIG. 4, preload directions of each of the bearings 11, 14, 37 and 38are shown. The preload direction (contact angle caused by a preload) isindicated by black thick solid lines on the bearings 11, 14, 37 and 38.

In the second driving side bearing 14, a preload is applied to thesecond driving side shaft part 72 c by the preload member 14 a so thatthe clearance on the inner ring side of the first driving side bearing11 side (right side in FIG. 4) becomes zero. That is, the right sideface of the inner ring of the second driving side bearing 14 contactsagainst the left side face of the enlarged diameter part of the seconddriving side shaft part 72 c.

In the first driving side bearing 11, a preload is applied to the firstdriving side shaft part 7 c so that the clearance on the inner ring sideof the second driving side bearing 14 side (left side in FIG. 4) becomeszero. That is, the left side face of the inner ring of the first drivingside bearing 11 contacts against the right side face of the enlargeddiameter part of the first driving side shaft part 7 c.

Therefore, the first driving side bearing 11 and the second driving sidebearing 14 are in a DB (back surface combination) preloading relation.As described above, the restraint in the axial direction of the drivingside scroll member 70 by each of the inner rings of the first drivingside bearing 11 and the second driving side bearing 14 suppressesdeformation in the direction in which the first driving side shaft part7 c and the second driving side shaft part 72 c of the driving sidescroll member 70 approaches each other.

Further, as described above, the application of the DB preload allowsthe deformation in the direction in which the distance between the innerring of the first driving side bearing 11 and the inner ring of thesecond driving side bearing 14 increases.

A preload is applied to the first support member shaft part 33 a so thatthe outer ring is urged toward the second support member bearing 38(left direction in FIG. 4) in the first support member bearing 37. Apreload is applied to the second support member shaft part 35 a so thatthe outer ring is urged toward the first support member bearing 37(right direction in FIG. 4) in the second support member bearing 38. Inthis manner, the first support member bearing 37 and the second supportmember bearing 38 are in a DF (front face combination) preloadingrelation. A preload is applied to the first support member bearing 37and the second support member bearing 38 when the motor housing part 3 aof the housing 3 and the scroll housing part 3 b are assembled by thebolts 32. That is, when the motor housing part 3 a and the scrollhousing part 3 b are contacted each other in the axial direction andtightened by the bolts 32, a preload is applied by displacing the outerrings of both bearings 37 and 38 fixed on the housing 3 side to approacheach other.

The co-rotating scroll compressor 1A having the above configurationoperates as follows.

The rotation of the drive shaft 6 around the driving side rotation axisCL1 by the motor 5 also rotates the first driving side shaft part 7 cconnected to the drive shaft 6 so that the driving side scroll member 70rotates around the driving side rotation axis CL1. The rotation of thedriving side scroll member 70 transmits the driving force from each ofthe support members 33 and 35 to the driven side scroll member 90 viathe pin ring mechanism 15 and rotates the driven side scroll member 90around the driven side rotation axis CL2. At this time, the movement ofthe pin member 15 b of the pin ring mechanism 15 in contact with thering member 15 a causes both the scroll members 70 and 90 to relativelyrevolve.

The revolving motion of both the scroll members 70 and 90 causes the airsucked from the suction port of the housing 3 to be sucked from theouter peripheral sides of both the scroll members 70 and 90 and takeninto the compression chambers formed by both the scroll members 70 and90. The compression chamber formed by the first driving side wall body71 b and the first driven side wall body 91 b, and the compressionchamber formed by the second driving side wall body 72 b and the seconddriven side wall body 92 b are compressed separately. As the taken airmoves toward the center side in each compression chamber, the volumedecreases, and accordingly the air is compressed. The air compressed bythe first driving side wall body 71 b and the first driven side wallbody 91 b passes through the through hole 90 h formed in the driven sideend plate 90 a, and combines with the air compressed by the seconddriving side wall body 72 b and the second driven side wall body 92 b.The combined air passes through the discharge port 72 d, and isdischarged from the discharge port 3 d of the housing 3 to the outside.The discharged compressed air is guided to an internal combustion enginewhich is not shown and is used as combustion air.

According to the present embodiment, the following operational effectsare obtained.

In the driving side scroll member 70, the first driving side bearing 11and the second driving side bearing 14 rotatably support each of theshaft parts 7 c and 72 c. The rotation of the driving side scroll member70 generates a centrifugal force to deform the driving side wall bodies71 b and 72 b of the driving side scroll member 70 radially outward (seeFIG. 5). As described above, the radially outward deformation of theouter peripheral side of the driving side scroll member 70 tends tocause the driving side scroll member 70 to deform to decrease a distanceto axial direction between the shaft part 7 c supported by the firstdriving side bearing 11 and the shaft part 72 c supported by the seconddriving side bearing 14, as shown by a broken line in FIG. 5(a). Suchallowance of the deformation further increases the deformation radiallyoutward on the outer peripheral side of the driving side scroll member70.

Therefore, in the present embodiment, a preload is applied to the firstdriving side shaft part 7 c so that an axial clearance in the seconddriving side bearing 14 direction is eliminated in the first drivingside bearing 11 and a preload is applied to the second driving sideshaft part 72 c so that an axial clearance in the first driving sidebearing 11 direction is eliminated in the second driving side bearing14. Thereby, as shown in FIG. 5(b), suppression of the deformation inwhich a distance to axial direction between the shaft parts 7 c and 72 csupported by each of the driving side bearings 11 and 14 decreases, canalleviate the stress generated in the driving side scroll member 70 andfurther suppress leakage of the compressed air generated by thedeformation of the driving side scroll member 70.

An increase of temperature during the operation in the co-rotatingscroll compressor 1A tends to cause the driving side scroll member 70 tothermally expand, and deform to increase a distance to axial directionbetween both the shaft parts 7 c and 72 c supported by each of thedriving side bearings 11 and 14. The restraint of the deformation leadsto the increase in the thermal stress generated in the driving sidescroll member 70 as shown in FIG. 6(a).

Therefore, the distal ends of the first driving side wall body 71 b andthe second driving side wall body 72 b is fixed to each other by the pin31 to allow displacement in the axial direction, and both the shaftparts 7 c and 72 c are supported by each of the driving side bearings 11and 14 to allow the increase in the distance between both the shaftparts 7 c and 72 c supported by the driving side bearings 11 and 14,that is, to allow the increase in the distance between the inner ring ofthe first driving side bearing 11 and the inner ring of the seconddriving side bearing 14. As a result, as shown in FIG. 6(b), thedistance between both the shaft parts 7 c and 72 c supported by each ofthe driving side bearings 11 and 14 can be increased according to thethermal expansion, so that the generation of the thermal stress can besuppressed.

Contacting the motor housing part 3 a and the scroll housing part 3 b ofthe housing 3 each other in the axial direction to be fixed by the bolts32 applies a preload to the first support member bearing 37 and thesecond support member bearing 38, so that it is unnecessary to providethe preload member for applying a preload. As a result, the number ofparts can be reduced, and assembling property is improved.

As for the driven side scroll member 90, similarly to the driving sidescroll member 70, in order to alleviate the deformation caused by thecentrifugal force and the thermal stress, the preload directions of thefirst support member bearing 37 and the second support member bearing 38may be set.

Second Embodiment

Next, a second embodiment of the present invention will be describedwith reference to FIG. 7.

In the first embodiment described above, double tooth, that is, two wallbodies of 71 b, 72 b, 91 b and 92 b are provided for each of the drivingside scroll member 70 and the driven side scroll member 90, but in thisembodiment, it is different in that one tooth, that is, one wall body isprovided for each of the driving side scroll member 7 and the drivenside scroll member 9. The same reference numerals are given to the sameconfigurations as those of the first embodiment, and the descriptionthereof is omitted.

The co-rotating scroll compressor 1B includes a driving side scrollmember 7 housed in a motor housing part 3 a of the housing 3 and adriven side scroll member 9 housed in the scroll housing part 3 b.

The driving side scroll member 7 has a driving side end plate 7 a and aspiral driving side wall body 7 b installed on one side of the drivingside end plate 7 a. The driving side end plate 7 a is connected to thedriving side shaft part 7 c connected to the drive shaft 6 and extendsin the direction orthogonal to the driving side rotation axis line CL1.The driving side shaft part 7 c is rotatably provided with respect tothe housing 3 via a driving side bearing 11 which is the angular ballbearing.

The driving side end plate 7 a has a substantially disk shape in a planview. Like the first driving side wall body 71 b shown in FIG. 2, thedriving side scroll member 7 provided with three, that is, triplespirals of the driving side wall bodies 7 b which are formed to spiral.The driving side wall bodies 7 b having triple spirals are arranged atequal intervals around the driving side rotation axis CL1.

The driven side scroll member 9 is arranged to engage with the drivingside scroll member 7, and has a driven side end plate 9 a and a spiralshaped driven side wall body 9 b installed on one side of the drivenside end plate 9 a. A driven side shaft part 9 c extending in thedirection of the driven side rotational axis CL2 is connected to thedriven side end plate 9 a. The driven side shaft part 9 c is rotatablyprovided with respect to the housing 3, via a driven side bearing 13which is the angular ball bearing.

The driven side end plate 9 a has a substantially disk shape in a planview. Like the first driven side wall body 91 b shown in FIG. 3, thedriven side scroll member 9 is provided with three, that is, triplespirals of the driven side wall bodies 9 b which are formed to spiral.The driven side wall bodies 9 b having triple spirals are arranged atequal intervals around the driven side rotation axis CL2. A dischargeport 9 d discharging the compressed air is formed substantially at thecenter of the driven side end plate 9 a. The discharge port 9 dcommunicates with a discharge port 3 d formed in the housing 3.

A driving side support member 20 is fixed to the distal end (free end)of the driving side wall body 7 b of the driving side scroll member 7via a pin 24 a. A driven side scroll member 9 is sandwiched between thedriving side support member 20 and the driving side scroll member 7.Therefore, the driven side end plate 9 a is arranged to face the drivingside support member 20.

The driving side support member 20 has a driving side support membershaft part 20 a on the center side, which is rotatably attached to thehousing 3 via a driving side support member bearing 26 which is theangular ball bearing. As a result, the driving side support member 20rotates around the driving side rotation axis CL1 like the driving sidescroll member 7.

A pin ring mechanism 15 is provided between the driving side supportmember 20 and the driven side end plate 9 a. The pin ring mechanism 15is used as the synchronous driving mechanism transmitting the drivingforce from the driving side scroll member 7 to the driven side scrollmember 9 so that both the scroll members 7 and 9 synchronously revolve.

A driven side support member 22 is fixed to the distal end (free end) ofthe driven side wall body 9 b of the driven side scroll member 9 via apin 24 b. A driving side scroll member 7 is sandwiched between thedriven side support member 22 and the driven side scroll member 9.Therefore, the driving side end plate 7 a is arranged to face the drivenside support member 22.

The driven side support member 22 has a driven side support member shaftpart 22 a on the center side, which is rotatably attached to the housing3 via a driven side support member bearing 28 which is the angular ballbearing. As a result, the driven side support member 22 rotates aroundthe driven side rotation axis CL2 like the driven side scroll member 9.

A pin ring mechanism 15 is provided between the driven side supportmember 22 and the driving side end plate 7 a. The pin ring mechanism 15is used as the synchronous driving mechanism transmitting the drivingforce from the driving side scroll member 7 to the driven side scrollmember 9 so that both the scroll members 7 and 9 synchronously revolve.

In FIG. 7, the preload directions of each of the bearings 11, 13, 26 and28 are shown. The preload direction (contact angle caused by a preload)is indicated by black thick solid lines on the bearings 11, 13, 26 and28.

In the driven side bearing 13, a preload is applied to the driven sideshaft part 9 c by the preload member 14 a so that the clearance on theinner ring side of the driven side support member bearing 28 side (rightside in FIG. 7) becomes zero. That is, the right side face of the innerring of the driven side bearing 13 contacts against the left side faceof the enlarged diameter part of the driven side shaft part 9 c.

In the driven side support member bearing 28, a preload is applied tothe driven side support member shaft part 22 a so that the clearance onthe inner ring side on the driven side bearing 13 side (left side inFIG. 7) becomes zero. That is, the left side face of the inner ring ofthe driven side support member bearing 28 contacts against the rightside face of the enlarged diameter part of the driven side supportmember shaft part 22 a.

Therefore, the driven side bearing 13 and the driven side support memberbearing 28 are in a DB (back surface combination) preloading relation.As described above, the restraint in the axial direction of the drivenside scroll member 9 by each of the inner rings of the driven sidebearing 13 and the driven side support member bearing 28 suppresses thedeformation in the direction in which the driven side shaft part 9 c ofthe driven side scroll member 9 and the driven side support member shaftpart 22 a approaches each other.

Further, as described above, the application of the DB preload allowsthe deformation in the direction in which the distance between the innerring of the driven side bearing 13 and the inner ring of the driven sidesupport member bearing 28 increases, according to the axial deformationof the driven side scroll member 9.

In the driving side bearing 11, a preload is applied to the driving sideshaft part 7 c so that the inner ring is urged in the direction of thedriving side support member bearing 26 (left direction in FIG. 7). Inthe driving side support member bearing 26, a preload is applied to thedriving side support member shaft part 20 a so that the inner ring isurged in the outward direction of the housing 3 (left direction in FIG.7).

A preload is applied to the driving side bearing 11 and the driving sidesupport member bearing 26 when the motor housing part 3 a and the scrollhousing part 3 b of the housing 3 are assembled by the bolts 32. Thatis, a preload is applied when the motor housing part 3 a and the scrollhousing part 3 b are contacted each other in the axial direction andtightened by the bolts 32.

The co-rotating scroll compressor 1B having the above configurationoperates as follows.

The rotation of the drive shaft around the driving side rotation axisCL1 by the motor also rotates the driving side shaft part 7 c connectedto the drive shaft so that the driving side scroll member 7 rotatesaround the driving side rotation axis CL1. The rotation of the drivingside scroll member 7 transmits the driving force from the driving sideend plate 7 a to the driven side support member 22 via the pin ringmechanism 15. In addition, the driving force is transmitted from thedriving side support member 20 to the driven side end plate 9 a via thepin ring mechanism 15. As a result, the driving force is transmitted tothe driven side scroll member 9, and the driven side scroll member 9rotates around the driven side rotation axis CL2. At this time, themovement of the pin member 15 b of the pin ring mechanism 15 in contactwith the ring member 15 a causes both the scroll members 7 and 9 torelatively revolve.

The revolving motion of both the scroll members 7 and 9 causes the airsucked from the suction port of the housing 3 to be sucked from theouter peripheral sides of both the scroll members 7 and 9, and takeninto the compression chambers formed by both the scroll members 7 and 9.As the taken air moves toward the center side in the compressionchamber, the volume decreases, and accordingly the air is compressed.The compressed air in this way passes through the discharge port 9 d ofthe driven side scroll member 9, and is discharged to the outside fromthe discharge port 3 d of the housing 3. The discharged compressed airis guided to an internal combustion engine which is not shown and usedas combustion air.

The operational effects according to the present embodiment are asfollows.

In the driven side scroll member 9 and the driven side scroll supportmember 22, the driven side bearing 13 and the driven side support memberbearing 28 rotatably support each of the shaft parts 9 c and 22 a. Therotation of the driven side scroll member 9 generates the centrifugalforce to deform the driven side wall bodies 9 b of the driven sidescroll member 9 radially outward (see, for example, the deformationshown in FIG. 5). As described above, the radially outward deformationof the outer peripheral side of the driven side scroll member 9 tends tocause the driven side scroll member 9 to deform to decrease a distanceto axial direction between the shaft part 9 c supported by the drivenside bearing 13 and the shaft part 22 a supported by the driven sidesupport member bearing 28 (see the broken line shown in FIG. 5(a), forexample). Such allowance of the deformation further increases thedeformation radially outward on the outer peripheral side of the drivenside scroll member 9.

Therefore, in the present embodiment, a preload is applied to the drivenside shaft part 9 c so that an axial clearance in the driven sidesupport member bearing 28 direction is eliminated in the driven sidebearing 13 and a preload is applied to the driven side support membershaft part 22 a so that an axial clearance in the driven side bearing 13direction is eliminated in the driven side support member bearing 28.Thereby, for example, similarly to the deformation shown in FIG. 5(b),the suppression of the deformation in which a distance to axialdirection between both the shaft parts 9 c and 22 a supported by each ofthe bearings 13 and 28 decreases, can alleviate the stress generated inthe driven side scroll member 9, further suppress the leakage of thecompressed air generated by the deformation of the driven side scrollmember 9.

The increase of temperature during the operation in the co-rotatingscroll compressor 1B tends to cause the driven side scroll member 9 tothermally expand, and deform to increase a distance to axial directionbetween both the shaft parts 9 c and 22 a supported by each of thebearings 13 and 28. The restraint of the deformation leads to theincrease in the thermal stress generated in the driven side scrollmember 9 as shown in FIG. 6(a), for example.

Therefore, the distal ends of the driven side wall body 9 b and thedriven side support member 22 are fixed by the pin 24 b to allow thedisplacement in the axial direction, and both the shaft parts 9 c and 22a are supported by each of the bearings 13 and 28 to allow the increasein the distance between both the shaft parts 9 c and 22 a supported byeach of the bearings 13 and 28, that is, to allow the increase in thedistance between the inner ring of the driven side bearing 13 and theinner ring of the driven side support member bearing 28. As a result,for example, similarly to the deformation shown in FIG. 6(b), thedistance between both the shaft parts 9 c and 22 a supported by each ofthe bearings 13 and 28 can be increased according to the thermalexpansion, so that the generation of the thermal stress can besuppressed.

Contacting the motor housing part 3 a and the scroll housing part 3 b ofthe housing 3 each other in the axial direction to be fixed by the bolts32 applies a preload to the driving side bearing 11 and the driving sidesupport member bearing 26, so that it is unnecessary to provide thepreload member for applying a preload. As a result, the number of partscan be reduced, and assembling property is improved.

As for the driving side scroll member 7, similarly to the driven sidescroll member 9, in order to alleviate the deformation caused by thecentrifugal force and the thermal stress, the preload directions of thedriving side bearing 11 and the driven side support member bearing 26may be set.

[Modification of how to Apply Preload]

In FIG. 8 to FIG. 23, there is shown a modification of how a preload isapplied to the bearings of the co-rotating scroll compressor 1A shown inthe first embodiment described above, that is, the modification of how apreload is applied to the both co-rotating scroll compressor ofdouble-teeth with two wall bodies of 71 b, 72 b, 91 b and 92 b providedfor each of the driving side scroll member 70 and the driven side scrollmember 90. Therefore, the same reference numerals are given to the sameconfigurations as those of the co-rotating scroll compressor 1A of thefirst embodiment, and the description thereof is omitted.

<Modification 1>

FIG. 8 shows a modification of how a preload is applied to the driveshaft 6 side, for the first embodiment.

In the second driving side bearing 14, an inner ring is loosely fittedto be fixed to be movable in the axial direction with respect to thesecond drive shaft part 72 c, and the outer ring is tightly fitted to befixed not to move in the axial direction with respect to the housing 3.

In the first driving side bearing 11, an inner ring is loosely fitted tobe fixed to be movable in the axial direction with respect to the firstdrive shaft part 7 c and the outer ring is tightly fitted to be fixednot to move in the axial direction with respect to the housing 3.

In the rear end bearing 17 provided at the rear end (the right end inFIG. 8) of the drive shaft 6, the inner ring is loosely fitted to befixed to be movable in the axial direction with respect to the driveshaft 6, and the outer ring is tightly fitted to be fixed not to move inthe axial direction with respect to the housing 3. On the right side ofthe rear end bearing 17, a preload member 17 a pressing the inner ringof the rear end bearing 17 toward the driving side scroll member 70 sideis provided. The preload member 17 a is a nut or the like, and isscrewed to the drive shaft 6. The application of a preload to the innerring of the rear end bearing 17 by the preload member 17 a causes a loadto be applied from the right side of the inner ring to the left side ofthe outer ring, as shown by the thick solid line in the figure.

The preload direction of the second driving side bearing 14 is thedirection from the right side of the inner ring to the left side of theouter ring and the preload direction of the first driving side bearing11 is the direction from the left side of the inner ring to the rightside of the outer ring. A preload is applied to the second driving sidebearing 14 and the first driving side bearing 12 when the motor housingpart 3 a and the scroll housing part 3 b of the housing 3 are contactedto be fixed by the bolts 32 in the axial direction.

According to such a configuration, the preload member is provided onlyon the rear end bearing 17, and it is not necessary to provide thepreload member on the first driving side bearing 11 and the seconddriving side bearing 14, so that the number of parts can be reduced.

FIG. 11 shows a combination of fitting of each bearing 11, 14 and 17 andpresence or absence of the preload member. In the same figure, theconfiguration described above is referred to as Modification 1-1.

As shown in Modification 1-2, the fitting between the second drivingside bearing 14 and the first driving side bearing 11 may be a movableloose in the axial direction for both the inner ring and the outer ring.Thereby, the attachment of the bearings 14 and 11 is facilitated and theassembling property improved.

In Modification 1-3, the inner ring of the second driving side bearing14 is set to loose and the outer ring of the second driving side bearing14 is set to tight, and the inner ring and the outer ring of the firstdriving side bearing 11 are set to tight. In this way, making the innerring of the first driving side bearing 11 tight also reduces themisalignment amount around the driving side rotation axis CL1. Inaddition, the first driving side bearing 11 is attached to the samemotor housing part 3 a as the motor 5, so that it is possible toreliably determine the positional relation with the motor 5.

In Modification 1-4, instead of tightening the inner ring of the firstdriving side bearing 11 as in Modification 1-3, the inner ring of therear end bearing 17 is set to tight. Even with such a configuration, itis possible to reduce the misalignment amount around the driving siderotation axis CL1. In this case, as shown in FIG. 9, a preload member 11a pressing the inner ring of the first driving side bearing 11 towardthe right side (rear end bearing 17 side) is provided without providingthe preload member 17 a with respect to the rear end bearing 17.

Further, as shown in FIG. 10, the preload member 14 a pressing the innerring of the second driving side bearing 14 toward the left side (sideopposite to the motor 5) may be provided.

<Modification 2>

As shown in FIG. 12, in Modification 2, the preload direction of therear end bearing 17 is different from that in Modification 1 describedabove, and the other preload directions are the same.

On the left side of the rear end bearing 17, the preload member 17 apressing the inner ring of the rear end bearing 17 toward the right side(in the direction opposite to the driving side scroll member 70 side) isprovided. The application of a preload to the inner ring of the rear endbearing 17 by the preload member 17 a causes the load to be applied fromthe left side of the inner ring to the right side of the outer ring, asshown by the thick solid line in the figure.

In addition, the preload member 11 a pressing the inner ring of thefirst driving side bearing 11 toward the right side (the rear endbearing 17 side) is provided.

FIG. 13 shows a combination of fitting of each of the bearings 11, 14and 17 and presence or absence of the preload member.

In Modification 2-1, the inner rings of each of the bearings 11, 14 and17 are set to loose and the outer ring is set to tight. And fixing thepreload members 11 a and 17 a and the housing 3 causes a preload to beapplied to each of the bearings 11, 14 and 17.

In Modification 2-2, setting the inner ring of the second driving sidebearing 14 to tight reduces the misalignment amount around the drivingside rotation axis CL1.

In Modification 2-3, setting the inner ring of the first driving sidebearing 11 to tight reduces the misalignment amount around the drivingside rotation axis CL1.

In Modification 2-4, setting all the inner rings and outer rings of eachof the bearings 11, 14 and 17 to loose facilitates the attachment ofeach of the bearings 11, 14, and 17, thereby improving assemblingproperty.

For each of Modifications 2-1 to 2-4, the preload member 14 a pressingthe inner ring of the second driving side bearing 14 toward the leftside (side opposite to the motor 5) may be provided as shown in FIG. 10.

<Modification 3>

As shown in FIG. 14, in Modification 3, the preload directions of thefirst driving side bearing 11 and the second driving side bearing 14 aredifferent from those of Modification 1 described above, and the preloaddirection of the rear end bearing 17 is the same.

In Modification 3-1, the preload members 11 a, 14 a and 17 a areprovided for each of the bearings 11, 14, and 17.

On the left side of the second driving side bearing 14, the preloadmember 14 a pressing the inner ring of the second driving side bearing14 to the right side (direction toward the driving side scroll member 70side) is provided. The application of a preload to the inner ring of thesecond driving side bearing 14 by the preload member 14 a causes theload to be applied from the left side of the inner ring toward the rightside of the outer ring, as shown by the thick solid line in the figure.

On the right side of the first driving side bearing 11, the preloadmember 11 a pressing the inner ring of the first driving side bearing 11toward the left side (the direction toward the driving side scrollmember 70 side) is provided. The application of a preload to the innerring of the first driving side bearing 11 by the preload member 11 acauses the load to be applied from the right side of the inner ring tothe left side of the outer ring, as shown by the thick solid line in thefigure.

On the right side of the rear end bearing 17, the preload member 17 apressing the inner ring of the rear end bearing 17 toward the left side(direction toward the driving side scroll member 70 side) is provided.The application of a preload to the inner ring of the rear end bearing17 by the preload member 17 a causes the load to be applied from theright side of the inner ring to the left side of the outer ring, asshown by the thick solid line in the figure.

FIG. 15 shows a combination of fitting of each of the bearings 11, 14and 17 and presence or absence of the preload member.

In Modification 3-2, the preload member 14 a of the second driving sidebearing 14 of Modification 3-1 described above is omitted, and the innerring of the second driving side bearing 14 is set to tight. As a result,the number of parts is reduced, and the misalignment amount around thedriving side rotation axis CL1 is reduced.

In Modification 3-3, the preload member 11 a of the first driving sidebearing 11 of Modification 3-1 described above is omitted, and the innerring of the first driving side bearing 11 is set to tight. As a result,the number of parts is reduced, and the misalignment amount around thedriving side rotation axis CL1 is reduced.

In Modification 3-4, the preload member 17 a of the rear end bearing 17of Modification 3-1 described above is omitted, and the inner ring ofthe rear end bearing 17 is set to tight. As a result, the number ofparts is reduced, and the misalignment amount around the driving siderotation axis CL1 is reduced.

<Modification 4>

As shown in FIG. 16, in Modification 4, the preload direction of therear end bearing 17 is different from that of Modification 3 describedabove, and the other preload directions are the same.

In Modification 4-1, on the left side of the rear end bearing 17, thepreload member 17 a pressing the inner ring of the rear end bearing 17toward the right side (in the direction opposite to the driving sidescroll member 70 side) is provided. The application of a preload to theinner ring of the rear end bearing 17 by the preload member 17 a causesthe load to be applied from the left side of the inner ring to the rightside of the outer ring, as shown by the thick solid line in the figure.

FIG. 17 shows a combination of fitting of each of the bearings 11, 14and 17 and presence or absence of the preload member.

In Modification 4-2, the preload member 14 a of the second driving sidebearing 14 of Modification 4-1 described above is omitted, and the innerring of the second driving side bearing 14 is set to tight. As a result,the number of parts is reduced, and the misalignment amount around thedriving side rotation axis CL1 is reduced.

In Modification 4-3, the preload member 11 a of the first driving sidebearing 11 of Modification 4-1 described above is omitted, and the innerring of the first driving side bearing 11 is set to tight. As a result,the number of parts is reduced, and the misalignment amount around thedriving side rotation axis CL1 is reduced.

In Modification 4-4, the preload member 17 a of the rear end bearing 17of Modification 4-1 described above is omitted, and the inner ring ofthe rear end bearing 17 is set to tight. As a result, the number ofparts is reduced, and the misalignment amount around the driving siderotation axis CL1 is reduced.

<Modification 5>

FIG. 18 shows a modification of how a preload is applied to the supportmember bearings 37 and 38 on the driven side, for the first embodiment.

In the second support member bearing 38, the inner ring is looselyfitted to be fixed to be movable in the axial direction with respect tothe second support member shaft part 35 a, and the outer ring is tightlyfitted to be fixed not to move in the axial direction with respect tothe housing 3. On the left side of the second support member bearing 38,a preload member 38 a pressing the inner ring of the second supportmember bearing 38 toward the driven side scroll member 90 side isprovided. The preload member 38 a is a nut or the like, and is screwedto the second support member shaft part 35 a. The application of apreload to the inner ring of the second support member bearing 38 by thepreload member 38 a causes the load to be applied from the left side ofthe inner ring to the right side of the outer ring, as shown by thethick solid line in the figure.

In the first support member bearing 37, the inner ring is loosely fittedto be fixed to be movable in the axial direction with respect to thefirst support member shaft part 33 a, and the outer ring is tightlyfitted to be fixed not to move in the axial direction with respect tothe housing 3. On the right side of the first support member bearing 37,the preload member 37 a pressing the inner ring of the first supportmember bearing 37 toward the driven side scroll member 90 side isprovided. The preload member 37 a is a nut or the like, and is screwedto the first support member shaft part 33 a. The application of apreload to the inner ring of the first support member bearing 37 by thepreload member 37 a causes the load to be applied from the right side ofthe inner ring to the left side of the outer ring, as shown by the thicksolid line in the figure.

According to such a configuration, similarly to the deformation shown inFIG. 5(b), the suppression of the deformation in which a distance toaxial direction between both the shaft parts 33 a and 35 a supported byeach of the bearings 37 and 38 decreases, can alleviate the stressgenerated in the driven side scroll member 90, further suppress theleakage of the compressed air generated by the deformation of the drivenside scroll member 90.

Further, for example, similarly to the deformation shown in FIG. 6(b),the distance between both the shaft parts 33 a and 35 a supported byeach of the bearings 37 and 38 can be increased according to the thermalexpansion, so that the generation of the thermal stress can besuppressed.

In FIG. 19, a combination of fitting of each of the bearings 37 and 38and presence or absence of the preload member is shown. In the samefigure, the above-described configuration is Modification 5-1.

In Modification 5-2, the inner ring of the second support member bearing38 is set to tight with respect to Modification 5-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2. In this case, the preload member 38 a of the secondsupport member bearing 38 can be omitted, and the number of parts can bereduced.

In Modification 5-3, the inner ring of the first support member bearing37 is set to tight with respect to Modification 5-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2. In this case, a preload member 37 a of the firstsupport member bearing 37 can be omitted, and the number of parts can bereduced.

<Modification 6>

As shown in FIG. 20, in Modification 6, the preload directions of eachof the bearings 37 and 38 are different from those of Modification 5described above.

On the right side of the second support member bearing 38, the preloadmember 38 a pressing the inner ring of the second support member bearing38 toward the left side (opposite direction to the driven side scrollmember 90 side) is provided. The application of a preload to the innerring of the second support member bearing 38 by the preload member 38 acauses the load to be applied from the right side of the inner ring tothe left side of the outer ring, as shown by the thick solid line in thefigure.

On the left side of the first support member bearing 37, the preloadmember 37 a pressing the inner ring of the first support member bearing37 toward the right side (opposite direction to the driven side scrollmember 90 side) is provided. The application of a preload to the innerring of the first support member bearing 37 by the preload member 37 acauses the load to be applied from the left side of the inner ring tothe right side of the outer ring, as shown by the thick solid line inthe figure.

A preload is applied to each of the bearing 37 and 38 when the motorhousing part 3 a and the scroll housing part 3 b of the housing 3 arecontacted to be fixed by the bolts 32 in the axial direction, it ispossible to omit the preload members 37 a and 38 a.

In FIG. 21, the fitting combination of each of the bearings 37 and 38 isshown. The preload members 37 a and 38 a can be omitted if a preload isapplied when the motor housing part 3 a and the scroll housing part 3 bof the housing 3 are contacted to be fixed by the bolts 32 in the axialdirection.

In Modification 6-1, the inner ring of each of the bearings 37 and 38 isset to be loose and the outer ring is set to tight.

In Modification 6-2, the outer rings of both the bearings 37 and 38 areset to loose with respect to Modification 6-1. Thereby, the attachmentof each of the bearings 37 and 38 is facilitated and the assemblingproperty improved.

In Modification 6-3, the inner ring of the second support member bearing38 is set to tight with respect to Modification 6-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2.

In Modification 6-4, the inner ring of the first support member bearing37 is set to tight with respect to Modification 6-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2.

<Modification 7>

As shown in FIG. 22, Modification 7 is different from the aboveModification 5 in that the preload members 37 a and 38 a are omitted,and the preload direction is the same. In addition, this modification isdifferent from Modification 5 in that the shaft part 33 a of the firstsupport member 33 is fitted to the outer ring of the first supportmember bearing 37, and the housing 3 is fitted to the inner ring of thefirst support member bearing 37. Similarly, this modification isdifferent from Modification 5 in that the shaft part 35 a of the secondsupport member 35 is fitted to the outer ring of the second supportmember bearing 38, and the inner ring of the second support memberbearing 38 is fitted to the housing 3.

A preload is applied to each of the bearing 37 and 38 when the motorhousing part 3 a and the scroll housing part 3 b of the housing 3 arecontacted to be fixed by the bolts 32 in the axial direction.

In FIG. 23, a combination of fitting of each of the bearings 37 and 38is shown.

In Modification 7-1, the inner ring of each of the bearings 37 and 38 isset to loose and the outer ring is set to tight.

In Modification 7-2, the outer rings of both the bearings 37 and 38 areset to loose with respect to Modification 7-1. Thereby, the attachmentof each of the bearings 37 and 38 is facilitated and the assemblingproperty is improved.

In Modification 7-3, the inner ring of the second support member bearing38 is set to tight with respect to Modification 7-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2.

In Modification 7-4, the inner ring of the first support member bearing37 is set to tight with respect to Modification 7-1. Thereby, it ispossible to reduce the misalignment amount around the driven siderotation axis CL2.

<Modification 8>

As shown in FIG. 24, the first driving side bearing 11 may be omitted,and the second driving side bearing 14 and the rear end bearing 17 maysupport the rotation around the driving side rotation axis CL1. As aresult, the number of parts can be reduced. In addition, as for apreload, as shown in FIG. 24, applying a preload by the rear end bearing17 instead of the first driving side bearing 11 can obtain the sameeffect as in the first embodiment.

In each of the above-described embodiments and modifications, theco-rotating scroll compressor is used as a supercharger, but the presentinvention is not limited to this, and it can be widely used as long asit compresses a fluid, and it can also be used as a refrigerantcompressor used in, for example, an air conditioner.

REFERENCE SIGNS LIST

-   1A, 1B, 1C Co-rotating scroll compressor-   3 Housing-   3 a Motor housing part (first housing)-   3 b Scroll housing part (second housing)-   3 c Cooling fin-   3 d Discharge port-   5 Motor (drive part)-   5 a Stator-   5 b Rotor-   6 Drive shaft-   7 Driving side scroll member-   7 a Driving side end plate-   7 b Driving side wall body-   7 c First driving side shaft part (driving side shaft part)-   9 Driven side scroll member-   9 a Driven side end plate-   9 b Driven side wall part-   9 c Driven side shaft part-   11 First driving side bearing-   11 Preload member-   14 Second driving side bearing-   14 a Preload member-   13 Driven side bearing-   15 Pin ring mechanism (synchronous driving mechanism)-   15 a Ring member-   15 b Pin member-   17 Rear end bearing-   17 a Preload member-   20 Driving side support member-   20 a Driving side support member shaft part-   22 Driven side support member-   22 a Driven side support member shaft part-   24 a Pin-   24 b Pin-   25 a Pin-   25 b Pin-   26 Driving side support member bearing-   28 Driven side support member bearing-   31 Pin (fixed portion of wall)-   32 Bolt-   33 First support member-   33 a First support member shaft part-   35 Second support member-   35 a Second support member shaft part-   37 First support member bearing (first driven side bearing)-   38 Second support member bearing (second driven side bearing)-   70 Driving side scroll member-   71 First driving side scroll part-   71 a First driving side end plate-   71 b First driving side wall body-   72 Second driving side scroll part-   72 a Second driving side end plate-   72 b Second driving side wall body-   72 c Second driving side shaft part-   72 d Discharge port-   73 Flange part-   90 Driven side scroll member-   90 a Driven side end plate-   90 h Through hole-   91 b First driven side wall body-   92 b Second driven side wall body-   CL1 Driving side rotation axis-   CL2 Driven side rotation axis-   P Dividing face

1. A co-rotating scroll compressor comprising: a driving side scrollmember rotatably driven by a drive part, having a plurality of spiraldriving side wall bodies installed with a predetermined angular intervalaround a center of a driving side end plate; a driven side scroll memberinstalled with a predetermined angular interval around a center of adriven side end plate, having a number of spiral driven side wall bodiescorresponding to each of the driving side wall bodies, and forming acompression space by engaging each of the driven side wall bodies withthe corresponding driving side wall bodies; a synchronous drivingmechanism transmitting driving force from the driving side scroll memberto the driven side scroll member so that the driving side scroll memberand the driven side scroll member synchronously revolve; a first drivingside bearing and a second driving side bearing rotatably supporting ashaft part of the driving side scroll member at one end side and theother end side in an axial direction; and a first driven side bearingand a second driven side bearing rotatably supporting a shaft part ofthe driven side scroll member at one end side and the other end side inthe axial direction, wherein a preload is applied to the shaft part sothat an axial clearance in a second driving side bearing direction iseliminated in the first driving side bearing, and a preload is appliedto the shaft part so that an axial clearance in a first driving sidebearing direction is eliminated in the second driving side bearing,and/or a preload is applied to the shaft part so that an axial clearancein a second driven side bearing direction is eliminated in the firstdriven side bearing, and a preload is applied to the shaft part so thatan axial clearance in a first driven side bearing direction iseliminated in the second driven side bearing.
 2. The co-rotating scrollcompressor according to claim 1, comprising: a driving side supportmember arranged via the driven side end plate, fixed to a distal endside in the axial direction of a driving side wall body and rotatingtogether with the driving side scroll member; and a driven side supportmember arranged via the driving side end plate, fixed to the distal endside in the axial direction of a driven side wall body and rotatingtogether with the driven side scroll member, wherein the first drivingside bearing supports the shaft part of the driving side scroll member,the second driving side bearing supports a shaft part of the drivingside support member, the first driven side bearing supports a shaft partof the driven side support member, and the second driven side bearingsupports the shaft part of the driven side scroll member.
 3. Theco-rotating scroll compressor according to claim 2, wherein the distalend side of the driving side wall body and the driving side supportmember are fixed to allow displacement in the axial direction, and eachof the shaft parts is supported by the first driving side bearing andthe second driving side bearing, to allow an increase in a distancebetween the shaft part supported by the first driving side bearing andthe shaft part supported by the second driving side bearing, and/or thedistal end side of the driven side wall body and the driven side supportmember are fixed to allow the displacement in the axial direction, andeach of the shaft parts is supported by the first driven side bearingand the second driven side bearing, to allow an increase in a distancebetween the shaft part supported by the first driven side bearing andthe shaft part supported by the second driven side bearing.
 4. Theco-rotating scroll compressor according to claim 1, comprising: thedriving side scroll member including a first driving side scroll parthaving a first driving side end plate and a first driving side wallbody, driven by the drive part, a second driving side scroll part havinga second driving side end plate and a second driving side wall body, anda fixed portion of wall fixing the distal ends of the first driving sidewall body and the second driving side wall body in a state in which thedistal ends of the first driving side wall body and the second drivingside wall body face each other in the axial direction, the driven sidescroll member including a first driven side wall body provided on oneside face of the driven side end plate, engaged with the first drivingside wall body, and a second driven side wall body provided on the otherside face of the driven side end plate, engaged with the second drivingside wall body, a first support member arranged via the first drivingside end plate, fixed to a distal end side in the axial direction of thefirst driven side wall body and rotating together with the first drivenside wall body, and a second support member arranged via the seconddriving side end plate, fixed to the distal end side in the axialdirection of the second driven side wall body and rotating together withthe second driven side wall body, wherein the first driving side bearingsupports a shaft part of the first driving side scroll part, the seconddriving side bearing supports a shaft part of the second driving sidescroll part, the first driven side bearing supports a shaft part of thefirst support member, and the second driven side bearing supports ashaft part of the second support member.
 5. The co-rotating scrollcompressor according to claim 4, wherein the fixed portion of wall isfixed to allow the displacement in the axial direction, and each of theshaft parts is supported by the first driving side bearing and thesecond driving side bearing, to allow the increase in the distancebetween the shaft part supported by the first driving side bearing andthe shaft part supported by the second driving side bearing, and/or thedistal end of each of the driven side wall bodies and each of thesupport members is fixed to allow the displacement in the axialdirection, and each of the shaft parts is supported by the first drivenside bearing and the second driven side bearing, to allow the increasein the distance between the shaft part supported by the first drivenside bearing and the shaft part supported by the second driven sidebearing.
 6. The co-rotating scroll compressor according to claim 1,comprising: a first housing having a bearing fixing part to which thefirst driving side bearing and the first driven side bearing are fixed;and a second housing contacted against and fixed to the first housing inthe axial direction, and having the bearing fixing part to which thesecond driving side bearing and the second driven side bearing arefixed, wherein a preload is applied to both the driving side bearingsand/or both the driven side bearings, by contacting the first housingand the second housing each other in the axial direction to be fixed. 7.The co-rotating scroll compressor according to claim 1, wherein thefirst driving side bearing is provided on a shaft part on an oppositeside sandwiching the drive part as seen from the driving side end plateof the driving side scroll member.